Stromal cells are classically defined as cells than make up the connective tissue of an organ, with their historical role to simply provide the architecture for the support of other functional cells within these organised tissues. However, rapidly emerging evidence suggests that stromal cells are far more deeply involved in the functional regulation of many tissues, organs, and in particular - immune responses.

Non-hematopoietic stromal cells, including fibroblasts, myofibroblasts, endothelial cells, pericytes, smooth muscle cells and mesenchymal stromal cells are now beginning to be appreciated as key cells required for the development and function of the immune system. In addition they are central to the persistence of many cancers and starting to be considered as functional cells in various immune-mediated diseases. They have been shown to present antigen, respond to pathogens, allow immune tolerance, educate functional responses of other immune cells, and to control wound healing. Indeed there are few immunological processes that stromal cells are not deeply involved in!

Thank you to Dr. Benjamin Owens, University of Oxford and Dr. Matt Lakins, University of Cambridge for their contributions to this page.